S-{107 -({107 -aminoalkylamino)alkyl dihydrogen phosphorothioates

ABSTRACT

Antiradiation agents of the formula RHN(CnH2n) NH(CnH2n) SPO3H2 wherein R is hydrogen or an alkyl group and each n is from 2 to 6, and hydrates or alkali metal salts thereof.

United States Patent [191 Piper et al.

S-a)-( w-AMINOALKYLAMINO )ALKYL DIHYDROGEN PHOSPHOROTHIOATES Inventors: James R. Piper; Thomas P.

Johnston, both of Birmingham, Ala.

Assignee: Southern Research Institute, Birmingham, Ala.

Filed: Dec. 16, 1968 Appl. No.: 784,231

US. Cl. 260/944, 260/979; 424/21 1 Int. Cl. C07f 9/16 Field of Search 260/944, 945

References Cited UNITED STATES PATENTS 1 H1946 Dickey et a] 260/945 July 1, 1975 3,124,508 3/1964 Nordmann 260/944 X Primary Examiner-Charles B. Parker Assistant Examiner-Richard L. Raymond Attorney, Agent, or Firm-Roylance, Abrams. Berdo & Kaul 5 Claims, No Drawings 1 S-w-( w-AMINOALKYLAMINO. )ALKYL DIHYDROGEN PHOSPHOROTHIOATES This invention relates to new compounds which are useful as antiradiation agents. More particularly, this invention relates to certain novel phosphorothioates as new compositions of matter.

The development of new antiradiation agents has been a matter of increasing interest in recent years. Such compounds are potentially useful in several different areas. Thus, for example, in X-ray therapy it is desirable to provide a drug which can be administered to a subject and which will then provide protection against the harmful effects of X-ray radiation. Antiradiation agents may also be useful in providing protection against other sources of harmful radiation such as may be encountered by personnel in the fringe areas of a nuclear explosion or by space travelers. Such agents should not only afford protection against radiation but must also be non-toxic in the dosage necessary to attain such protection.

It is an object of this invention to provide a new class of compounds which, upon administration to a subject, will provide protection against the harmful effects of radiation.

It is a further object of this invention to provide such compounds of sufficiently low toxicity that they will be easily tolerated at levels which will result in a long duration of action while maintaining effective radioprotection.

These and other objects are achieved by the practice of this invention which, briefly, comprises providing compounds of the formula RNH(C,,H ,,)NH(C,,l-l- ,,)SPO H wherein R is hydrogen or an alkyl group containing from 1 to 7 carbon atoms and each n has a value of from 2 to 6; or hydrates and/or alkali metal salts thereof.

The novel compounds of this invention may be prepared by methods known in the art, see, for example, F. Cortese, Organic Syntheses, Coll. Vol. 11, A. H. Blatt, ECL, John Wiley and Sons, Inc., New York, N.Y., 1943, pages 91 to 93; S. Akerfeldt, Acta Chem. Scand, 14, 1980 (1960); and J. R. Piper et a1., Chem. Ind. (London), 2010 (1966).

The antiradiation agents of this invention may be administered, for example, intraperitoneally from to 30 minutes before irradiation in the form ofa 0.3 to 5.0 percent by weight solution or suspension.

The following examples illustrate the best modes contemplated for carrying out this invention:

EXAMPLE 1 Preparation of Dihydrogen Phos Monohydrate aid of several added portions of methanol. The crystalline residue was thoroughly triturated with acetone, collected, and washed on the funnel with acetone. After the product had been pressed as dry as possible on the funnel, it was dissolved in a slight excess of boiling methanol and the solution was filtered. Addition of acetone to the filtrate precipitated pure N-(2-bromoethyl)-l,3-propanediamine dihydrobromide as colorless crystals, which were dried in vacuo over phosphorus pentoxide: yield 58.0 g mp 2052O6C.

Trisodium phosphorothioate (6.93 g, 38.5 mmoles) was gradually added in small portions with vigorous stirring to water (38 ml) cooled externally by means of a water bath (l5-20C.). To the resulting suspension was added N-(2-bromoethyl)-l,3-propanediamine dihydrobromide (13.3 g, 38.8 mmoles). After a few minutes, complete solution occurred, and N,N-dimethylformamide (19 ml) was added with continued external cooling at l520C. I

After the solution had been stirred at about 20C. for minutes, it was poured into methanol (250 ml), and the mixture was refrigerated at 4C. overnight. The white precipitate that formed was collected and pressed as dry as possible on the funnel. The damp solid was dissolved in water (40 ml), and the solution was filtered. Addition of methanol (250 ml) reprecipitated the product. After the mixture had been refrigerated about 1 hour, the product was collected and washed on the funnel, first with methanol and finally with ether. The white solid was dried in vacuo at room temperature, then exposed to ambient conditions of the laboratory for 5 hours, and bottled under nitrogen and stored in a freezer. The yield of S-2-( 3- aminopropylamino)ethy1 dihydrogen phosphorothioate monohydrate, mp 160-161C. dec, was 8.15 g (91%). Anal. Calcd for C5H15NgO3PS.HgO: C, 25.86; H, 7.38; N, 12.07. Found: C, 25.83; H, 7.27; N. 11.81.

EXAMPLE 2 Preparation of S-3-(3-Aminopropylamino)propyl Dihydrogen Phosphorothioate Dihydrate H N(Cl-l- );,NH(CH SPO;,H .2H O

A solution of N-(3-bromopropyl)phthalimide (21.8 g, 81.1 mmoles) and tetrahydro-ZH- 1 ,3-oxazin-2one (8.20 g, 81.1 mmoles), in N,N-dimethylformamide ml) was added dropwise over a 30 minute period to a stirred mixture of sodium hydride (60% NaH in oil dispersion; 3.24 g, 81.1 mmoles) in N,N-dimethylformamide (25 ml) with moderate external cooling so that the reaction temperature did not exceed 25C. After the mixture had been stirred overnight at room temperature, the solvent was removed by distillation in vacuo. The residue was stirred thoroughly with water (200 ml), and the water-insoluble, off-white solid was collected and dried in vacuo over phosphorus pentoxide. Recrystallization of the crude solid 18.0 g) from toluene afforded 3-(3-phthalimidopropyl)tetrahydro-2l-i- 1,3-oxazin-2-one, mp 133135C., in 62% yield (14.5

A stirred solution of 3-( 3- phthalimidopropyl)tetrahydro-ZH-1 ,3-oxazin-2-one 12.0 g, 41.6 mmoles) in 30 percent hydrogen bromide in acetic acid solution (80 ml) was slowly heated to re flux and was maintained under reflux for 0.5 hour. The cooled solution was diluted with ether (about 230 ml); and the crystalline product that separated in essentially theoretical yield was collected, washed with ether, and dried at 77C. in vacuo over phosphorus pentoxide. Re-

crystallization from 95 percent ethanol gave 15.1 g (89%) of N-[3-( 3-bromopropylamino)propyl]phthalimide hydrobromide, mp 199-200C.

A stirred mixture of N-[3-(3-bromopropylamino)- propyl]phthalimide hydrobromide (13.0 g, 32.0 mmoles), 48 percent hydrobromic acid (50 ml), and glacial acetic acid (50 ml) was heated to reflux, complete solution occurring before reflux commenced. The solution was heated under reflux overnight 17 hours). The cooled solution gradually deposited phthalic acid, which was removed by filtration. The filtrate was evaporated to dryness and the white crystalline residue was dissolved in methanol and reprecipitated by the addition of ether. The material thus obtained (10.9 g) was then recrystallized from ethanol to give pure N-(3- bromopropyl)-1 ,3-propanediamine dihydrobromide, mp 243245C. dec, in 83 percent yield (9.35 g).

N-( 3-Bromopropyl)-1 ,3-propanediamine dihydrobromide (3.57 g, 10.0 mmoles) was added to a stirred partial solution of trisodium phosphorothioate 1.80 g, 10.0 mmoles) in water (10 ml), and stirring was continued until complete solution occurred. The solution was kept at 25-30C. for 2 hours and cooled to about 4C. and N,N-dimethylformamide (5 ml) was added with stirring. Crystalline product separated immediately. Ethanol (100 ml) was added and the solid was collected, washed with ethanol, redissolved in water (60 ml), and reprecipitated by the addition of ethanol. The mixture was cooled to precipitate the product which was washed with ethanol and dried at 2530C. in vacuo over sodium hydroxide pellets. Pure S-3-(3- aminopropylamino)propyl dihydrogen phosphorothioate dihydrate, mp l40l43C. dec, was obtained in 92% yield (2.42 g). Anal. Calcd for C H N- O PS2- H O: C, 27.27; H, 8.01; N, 10.60; P, 11.72; S, 12.14. Found: C, 27.19; H, 7.78; N, 10.58; P, 11.73; S, 12.02.

EXAMPLE 3 Preparation of S-2-(3-Ethylaminopropylamino)ethyl Dihydrogen Phosphorothioate Hydrate CH=,CH NH(CH NHCH CH SPO H .l .SH O

A stirred mixture of N-ethyl-p-toluenesulfonamide (39.9 g, 0.200 mole), potassium carbonate (30.0 g, 0.218 mole), 3-(3-chloropropyl)-2-oxazolidinone (33.0 g, 0.202 mole), and N,N-dimethylformamide (300 ml) and was heated at l12OCv for 3 hours. The mixture was allowed to cool to room temperature and was then poured into water 1.2 1.). The orange oil that separated was extracted from the aqueous mixture with two 500-ml portions of benzene; and the benzene solution was washed with water and dried over anhydrous magnesium sulfate. Benzene was removed from the clear filtered solution by evaporation under reduced pressure. Crude N-ethyl-N-[3-(2-oxo-3- oxazolidinyl)propyl]-p-toluenesulfonamide amounting to 58.5 g (90 percent yield) remained as an orange oil.

The crude N-ethyl-N-[3-(2-oxo-3- oxazolidinyl)propyl]-p-toluenesulfonamide (58.0 g, 0.178 mole) described above was dissolved along with phenol (19 g, 0.20 mole) in 30-32 percent hydrogen bromide in acetic acid solution (200 ml), and the mix ture was stirred at room temperature for 3 days. Additional 30-32 percent hydrogen bromide in acetic acid solution 100 ml) was added, and the mixture was gradually heated to boiling and maintained under reflux for 24 hours. The cooled mixture, from which the product crystallized in crude form, was mixed with ether 1 1.).

to cold (5C.)"48 percent hydrobromic acid (90 ml),

The crude product was collected and washed thoroughly on the funnel with ether and acetone. The solid was then recrystallized from methanol, collected with the aid of ethanol, and dried in vacuo over phosporus pentoxide to give 46.4 g percent yield) of pure N- (2-bromoethyl)-N-ethyl-1,3-propanediamine dihydrobromide,mp 262263C. dec.

Pure N-( 2-bromoethy1)-N '-ethyl-1,3- propanediamine dihydrobromide 14.8 g, 40.0 mmoles) was added to a stirred partial solution of trisodium phosphorothioate (7.20 g, 40.0 mmoles) in water (40 ml). After a few minutes of continued stirring, N,N-dimethylformamide (20 ml) was added. The resultant solution was kept at room temperature for 1 hour and was then chilled in an ice-water bath and stirred rapidly while N,N-dimethylformamide 100 ml) was added dropwise. The white precipitate that formed was collected with the aid of ethanol, washed thoroughly with ethanol and ether, and dried. The dried solid was dissolved in water and the solution was filtered. The filtrate was cooled in an ice bath and ethanol was added dropwise, causing precipitation of S-2-( 3- ethylaminopropylamino)ethyl dihydrogen phosphorothioate as white crystals. The product was collected, washed successively with ethanol and ether, and air dried to constant weight (9.72 g). The yield of hydrated product, mp 143-145C. was percent. Anal. Calcd for C H, N O PS.1.5H O: C, 31.22; H. 8.23; N, 10.40; P, 11.50; S, 11.91. Found: C, 31.24; H, 7.94; N, 10.43; P, 11.1; S, 12.3.

EXAMPLE 4 Preparation of S-2-( 3-Aminopropylamino)-2-methylpropyl Dihydrogen Phosphorothioate Hydrate 2,2-Dimethylaziridine g, l .41 moles) was added to stirred, freshly distilled acrylonitrile (64.7 g, 1.20

moles), and the resulting solution was heated to boiling and maintained under reflux for 12 hours. During this time the reflux temperature rose from 78 to 138C. Fractionation in vacuo afforded 2,2-dimethyl-1- aziridinepropionitrile.

A solution of 2,2-dimethyl-l-aziridinepropionitrile (28.0 g, 0.254 mole) in ether (250 ml) was added dropwise to a mechanically stirred suspension of lithium aluminum hydride (10.6 g, 0.279 mole) in ether (250 ml). Stirring was continued for 6 hours. The mixture was then chilled in an ice-water bath and water 10 ml) was slowly added dropwise with vigorous stirring. Sodium hydroxide solution (20 percent, 8 ml) was then added dropwise followed by more water (35 ml). The mixture was stirred for 1 hour and filtered, and the filter cake washed with ether. Removal of the solvents 1 from the combined filtrate and washings left an oily crude product, purification of which by vacuum distillation gave 24.0 g (74 percent yield) of 1-( 3- aminopropyl)-2,2-dimethylaziridine as a colorless oil.

l-(3 Aminopropyl) -2,2-dimethylaziridine (24.0 g, 0.206 mole) was added dropwise and with rapid stirring the temperature being maintained between 5 and 0C. throughout the addition. The clear solution was evaporated to dryness and the residue was stirred with acetone. The acetone-insoluble white solid was collected, washed with acetone and ether, and dried in vacuo over phosphorus pentoxide. The crude product (61.7 g) was purified by a recrystallization from methanol-acetone followed by two reprecipitations from methanol solution by the addition of ether. Pure N-(2- bromo-l ,1-dimethy1ethy1)-l ,3-propanediamine dihydrobromide, mp l88-189C., was obtained in 54 percent yield (41.8 g).

A solution of N-(2-bromo-1.l-dimethylethyl)-l,3- propanediamine dihydrobromide (4.45 g, 12.0 mmoles) and trilithium phosphorothioate hexahydrate (2.88 g, 12.0 mmoles) in water (12 ml) was stirred at -30C. for minutes. N,N-Dimethylformamide (6 ml) was added, and after 15-20 minutes the solution began depositing crystalline product. The mixture was refrigerated overnight. Ethanol ml) was added and the product was collected, washed with ethanol, redissolved in water (20 ml), and then reprecipitated by the addition of ethanol (100 ml). Hydrated S-2-(3- aminopropylamino)-2-methylpropyl dihydrogen phosphorothioate was collected, washed with ethanol followed by ether, air dried, and equilibrated at 58 percent relative humidity. The product, yield 93 percent (3.21 g), formed an opaque melt at about 149-154C. Ana]. Calcd for CT lbNgOzgPS-Z-SH OI C, 29.26; H, 8.41; N, 9.75; P, 10.79; S, 11.16. Found: C, 29.05; H, 8.10; N, 9.57; P, 11.2; S, 11.6.

Each of the foregoing compounds was evaluated by the Walter Reed Army Institute of Research as radioprotective agents in mice exposed to lethal radiation by a testing procedure described by L. Field et al., J. Med.

Chem.. 7, 39 1964). The drugs were injected intraperitoneally as a 0.3-5.0 percent solution or suspension 15 to 30 minutes before irradiation in the dosages set forth in Table 1. In this table, the dosage is given in mg. of compound per kg. of body weight of the mice. The mice were then exposed to lethal radiation, i.e.. 825 roentgens of X-rays or 950 to 1050 roentgens of gamma rays. Table 1 sets forth the percentage of animals surviving at the end of 30 days. There was no 30 day survival among control mice, i.e., ones which received no antiradiation agent. The LD.-,.. dosages of the compounds tested are also set forth in Table I.

By the general procedures described in the literature cited hereinabove and specifically exemplified in Examples 1 to 4, several additional antiradiation agents were synthesized and were evaluated as radioprotective agents in the manner previously described. The results are set forth in Table 11, below.

gable II Compound Approximate Drug Vehicle pH of 30-Day LD rug/kg dose, of adminprepn survival,

mg/kg istration 0 H N(CH NH(CH S PO3H H 0 1300 800 Water 6.1 100 1400 Water 6.1 100 200 Saline 6.5 27 100 Saline 6.5 0

H N(cH NH(cH sPo H 800 M00 Water 7.0 100 200 Water 7.0 Saline 7.6 13

11 M05 NH(cH sP03H .H o

550 300 Water 6 9 100 Water 6.0 100 75 Saline 7.2 13 'H N(cH im(oH sPo H .H 0

Y 55o 300 Water 7.0 87 200 Saline 7.2 no 150 Water 7.0 93 100 Saline 7.2 0

gable II -Continued Compound Approximate Drug Vehicle pH of 30Day LD dose, of adminprepn survival,

rug/kg, istration o H N(CH NH(CH2)3SPO3H2 I 1300 1000 CMC-Tw 6.5 100 800 CMC-Tw 6.5 83 500 CMC-Tw 6.5 100 11,00 GMC-TW 6.5 67 200 CMC-Tw 6.5 13 CH HEN (CH2 )3m'lCHCH2SPO3H2 2 EH20 11,50 al o Water 50 CH NH (CH NH(CH SPO H 2.53

900 t oo PB 6. 9 73 200 PB 6.9

CH NH(CH NH(CH SPO H H 0 800 L .O0 PB 7.0 100 200 PB 7 .0 7 100 PB 7 .5 Lie 5 PB 755 13 In Tables I and Il, under the columns headed Vehicle gen or an alkyl group containing from 1 to 7 carbon atoms and each n has a value of from 2 to 6; and hydrates or alkali metal salts thereof.

2'. S-2-(3-Aminopropylamino)ethyl dihydrogen phosphorothioate hydrate.

3. S-3-(3-Aminopropylamino)propyl phosphorothioate hydrate.

4. S-2-(3-Methylaminopropylamino)ethyl dihydrogen phosphorothioate hydrate.

5. S-2-(3-Ethylaminopropylamino)ethyl dihydrogen phosphorothioate hydrate.

dihydrogen 

1. COMPOUNDS OF THE FORMULA RHN(CNH2N)NH(CNH2N)SPO3H2 WHEREIN R IS HYDROGEN OR AN ALKYL GROUP CONTAINING FROM 1 TO 7 CARBON ATOMS AND EACH N HAS A VALUE OF FROM 2 TO 6, AND HYDRATES OR ALKALI METAL SALTS THEREOF.
 2. S-2-(3-Aminopropylamino)ethyl dihydrogen phosphorothioate hydrate.
 3. S-3-(3-Aminopropylamino)propyl dihydrogen phosphorothioate hydrate.
 4. S-2-(3-Methylaminopropylamino)ethyl dihydrogen phosphorothioate hydrate.
 5. S-2-(3-Ethylaminopropylamino)ethyl dihydrogen phosphorothioate hydrate. 